Height adapter for foldable trampolines



FEB. 14, 1967 G, N S EN ETAL 3,303,905

HEIGHT ADAPTER FOR FOLDABLE TRAMPOLINES Filed Oct. 4, 1965 i ]N VENIORS GEORGE P NISSEN HARLAN KELLY m 3 f ATTORNEY United States Patent 3,303,905 HEIGHT ADAPTER FOR FOLDABLE TRAMPOLINES George P. Nissen and Harlan J. Kelly, Cedar Rapids,

Iowa, assignors to Nissen Corporation, Cedar Rapids,

Iowa, a corporation of Iowa Filed Oct. 4, 1965, Ser. No. 492,512 6 Claims. (Cl. 182-137) This invention concerns trampoline apparatus, especially foldable trampolines of large size, and is particularly directed to an adapter therefor which lowers the overall height of the folded trampoline when transported upon a pair of roller stands.

Large trampolines of the kind concerned may have overall dimensions on the order of 17 long, 10 wide and 3'5" high when erected for use. Folded and in the position illustrated in FIGURE 5 of US. Patent 3,116,809 to George P. Nissen, they may have overall dimensions on the order of wide, 9" thick and 6'7" high. Typically, such trampolines in their folded conditions are transported on roller stands of the nature and in the manner shown in the aforesaid patent. In such case, the overall height of the folded trampoline may be well in excess of the height of many gymnasium doors, thus presenting a problem during the moving and storage of the folded trampoline. It is most important that such transport and storage be readily achieved in order that the gymnasium floor can be easily and quickly cleared for other apparatus or activity.

Typically, as shown in the aforesaid patent, the roller stands are attached to sleeves or bushings located centrally along the intermediate side frame members of the trampoline. Therefore, the effective height of the roller stands in such cases must be greater than one-half the height of the folded trampoline when in the position shown in FIGURE 5 of the aforesaid patent, that is to say, more than 3'3 /2". However, in order to be high enough to be fitted to the erected trampoline in the manner shown in FIGURE 3 of the aforesaid patent, the effective height of the roller stands must be substantially in excess of 3'5, the height of the erected trampoline before folding. In fact, the roller stands must raise the trampoline above the fioor enough to permit the splayed leg members thereof (designated at 14 in the aforesaid patent) to be swung up under the trampoline without being impeded by the floor. Thus, the height of the roller stands must at least equal the length of such leg members, the effective height of the particular roller stands employed with the aforesaid trampoline being either 45 or 48". Accordingly, the problem of passage of the folded trampoline upon roller stands through many gymnasium doors cannot be solved merely by reducing the height of the roller stands themselves.

It is thus the primary object of the present invention to eliminate the foregoing problem by means which may be easily and economically incorporated into trampolines of the kind concerned, especially those now in the field. Briefly described, the present invention consists of a pair of height adapters clamped to the sides of the trampoline frame in fitted engagement with the aforesaid bushings for the roller stands. Each adapter when so clamped provides a pair or" alternate bushings, each horizontally disposed to one side of the main or centrally located bushing. The alternate bushings thus permit the folded trampoline to be mounted asymmetrically on the roller stands, the longer folded portion of the trampoline extending downwardly from the roller stand trunnions and so reducing the overall height thereof. The roller stands themselves are necessarily of suflicient height, for the reasons previously mentioned, to permit the folded trampoline thereon to be appreciably lowered without the lower end thereof striking the floor. Other and further objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred form thereof, being the best mode contemplated for carrying out the present invention, read in conjunction with the drawings, in which:

FIGURE 1 is a perspective view of one of a pair of height adapters according to the present invention;

FIGURE 2 is a partial perspective view of one side of a trampoline with the height adapter for that side in place and a roller stand in position for elevating and folding of the trampoline for transport;

FIGURE 3 is a view taken along the lines 3-3 of FIGURE 2, certain of the parts being broken away; and

FIGURE 4 illustrates the folded trampoline, equipped with the height adapters of the present invention, mounted upon the roller stands ready for transport.

In the drawings 10 designates one of the two intermediate side rails of a trampoline frame spacedly surrounding the trampoline bed (not shown) from which the latter is resiliently suspended in the customary manner. The outer ends 10', 10" of the trampoline frame are foldable inwardly and overlappingly in the manner shown in US. Patent 2,969,124 to George P. Nissen by virtue of two pairs of hinge joints attached to the respective abutting ends of side rails 10 and outer ends 10', 10" of the trampoline frame, the hinge joints at the ends of side rail 10 being indicated at 11, 11 in the drawings. An open ended, main pivot sleeve or bushing 12 is fixed beneath side rail 10 coaxial with a horizontal center line A-B in the transverse center plane of the trampoline. Laterally disposed from bushing 12 beneath the hinge joints 11, 11 a similar pair of pivot sleeves or bushings 13, 13 are also secured to the under side of side rail 10, their pivot axes being parallel to that of bushings 12. The under sides of bushings 12 and 13, 13' in turn are connected by an auxiliary or tie rail 14 terminating at bushings 13, 13'. The main bushing 12 may removably and pivotally receive the trunnion 15 of one of a pair of roller stands 16 (only one being shown) of the nature illustrated in the aforesaid patents. The bushings 13, 13 removably and pivotally receive the upper ends of leg members 17, 17 (see FIGURES 2 and 4) which are foldable upwardly and overiappingly under the trampoline frame in the manner shown in the aforesaid Patent 3,116,809. It will be understood, of course, that other supporting members, such as chain 18 are also employed and are foldable as shown in the aforesaid patents.

Each height adapter 29 comprises a pair of short lengths of flattened tubular members 21 sized so that they may he slipped horizontally between side and auxiliary rails 19 and 14. Tubular members 21 may in fact be identical in nature to side rail Iii and are spaced endwise from each other by means of a fixed plate 22 welded to the sides of each and spanning the space between their inner ends 23, the spacing between the latter being suflicient to receive main bushing 12 transversely therebetween. A retaining plate 24 is removably secured, as by bolts 25 and nuts 26 welded to the interior walls of members 21, to the opposite sides of the latter parallel to fixed plate 22 and also spanning the inner ends 23 of members 21. The outer ends of a pair of coaxial mounting bosses or bushings 27, 27 fittable within the open ends of main bushing 12, are secured to the opposing inner faces of plates 22 and 24 and centrally spaced between the inner ends 23 of members 21. To the outer ends of members 21 are secured the side walls of a pair of alternate pivot sleeves or bushings 28, 28' identical in size with main bushing 12 whose axes are parallel to that of mounting bushings 2'7, 27. It will be understood, of course, that the structure on the other side of the trampoline and the adapter therefor is identical to the foregoing.

Each adapter 20 is secured to its respective side of the trampoline by first removing bolts 25 and then retaining plate 24 so that the adapter 20 may be slipped between its respective side and auxiliary rails and 14 with its mounting bushing 27 engaged within the outer end of the appropriate main bushing 12. Retaining plate 24 is then reattached with bolts 25 so that its mounting bushing 27 is engaged within the other end of the aforesaid bushing 12, thus securing each adapter 20 to the trampoline and providing in effect two alternate pivot bushings 28, 28 for the trunnions 15 of roller stands 16, one to each side of the center line A-B. Accordingly, when the roller stands 16 are inserted as shown in FIGURE 2 into the right hand pair of alternate bushings 28 and the trampoline folded and swung from the horizontal to the vertical position shown in FIGURE 4', the lower end of same will be nearer the fioor and the overall height of the folded trampoline reduced by the distance between the center line A-B and alternate bushings 28, the axes of bushings 12 and alternate bushings 28 thus lying below that of the alternate bushings 28. The reason two pairs of alternate pivot bushings 28, 28' are employed is so that no matter which pair of the outer frame ends 10, 10" and leg members 17, 17 is folded over the other, the roller stands 16 may be inserted in that pair of alternate bushings 28, 28' which will result (as in FIGURE 4) in the outer overlapping frame end 10 and leg member 17' when folded having their hinge joints 11 and bushings 13' at the top when the folded trampoline is swung upright on the roller stands 16, thus maintaining the outer frame ends 10', 10" and leg members 17, 17 in their folded condition. If the other pair of alternate bushings 28, 28' were used, so that hinge joints 11 and bushings 13 were at the bottom in FIGURE 4, the folded frame ends 10', 10 and leg members 17, 17 would tend to unfold. The requisite spacing between alternate bushings 28, 28' will vary, of course, depending upon the size of the trampoline and roller stands involved. In the case of trampolines and roller stands of the dimensions stated above, a spacing of about 12 between the axes of alternate bushings 28, 28 works very well, giving an effective height reduction of 6".

Though the present invention has been described with respect to a particular embodiment thereof and detailed descriptive language has been used, it is not so limited. Instead, the following claims are to be read as encompassing all modifications and adaptations of the invention falling within the spirit and scope thereof.

We claim:

1. In a folding trampoline having a frame including laterally spaced side members, said side members having a pair of main pivot means disposed midway therealong for removably receiving the upper ends of a pair of roller stands of the kind described for carrying said trampoline when folded over a gymnasium fioor, said main pivot means being effective when the folded trampoline is being carried by said roller stands to permit the folded trampoline to be rotated thereabout on a first axis extending centrally and transversely between said side members to an upright position wherein the lower end of the folded trampoline is spaced above the floor, the combination therewith of a pair of height adapters securable to said side members, said adapters including a pair of alternate pivot means carried thereby for removably receiving theupper ends of said roller stand for rotation of the folded trampoline thereabout on a second axis parallel to said first axis, said second axis being laterally disposed to one side of said first axis effective to lower the folded trampoline toward the floor when carried by said roller stands and alternate pivot means and rotated thereabout to an upright position in which said first axis is disposed below said second axis.

2. The combination of claim 1 wherein each pair of said main and alternate pivot means includes a pair of open-ended bushings coaxial with said first and second axes respectively.

3. The combination of claim 2 wherein said adapters include a second pair of alternate pivot means comprising a pair of bushings providing a third axis laterally disposed to the other side of said first axis effective to lower the folded trampoline toward the fioor when carried by said roller stands and second pair of alternate pivot means and rotated thereabout to an upright position in which said first and second axes are disposed below said third axis.

4. The combination of claim 3 wherein each of said adapters is provided with means to removably secure same to said side members, said securing means including a pair of coaxial bosses having opposed ends fitting within the opposite ends of one of said main bushings, the remaining ends of said bosses being carried by a pair of laterally spaced retaining members, one of said members being fixed to said adapter and the other of said members being removably secured thereto.

5. A removable height adapter for use with folding trampolines having a pair of side rails forming a portion of the frame thereof, a pair of auxiliary rails concurrent with said side rails and spaced therebelow, and a pair of open ended, coaxial main pivot bushings disposed between said side and auxiliary rails and secured thereto, the axis of said bushings extending centrally and transversely between said side rails, said adapter comprising a body portion, a pair of laterally spaced, alternate pivot bushings having parallel axes carried by said body portion, a boss fixed to said body portion and removably securable to one of said main pivot bushings, the axis of said boss being disposed parallel to and between the axes of said alternate pivot bushings, and removable means carried by said body to maintain said boss secured to said main pivot bushing.

6. A removable height adapter for use with a folding trampoline having a pair of side rails forming a portion of the frame thereof, a pair of auxiliary rails concurrent'with said side rails and spaced therebelow, and a pair of openended, coaxial main pivot bushings disposed between said side and auxiliary rails and secured thereto, the axis of said bushings extending centrally and transversely between each pair of said side and auxiliary rails, said adapter comprising a pair of relatively short body members disposed in end to end aligned relationship with their opposed inner ends spaced apart effective to permit one of said main pivot bushings to be inserted therebetween so that the axis of said bushing lies transversely of said body members, a pair of alternate pivot bushings fixed to the outer ends of said body members, said last named bushings having their axes parallel with respect to each other and transversely with respect to said body members, a fixed plate and a retaining plate laterally spaced from each other effective to encompass the length of said main pivot bushing therebetween and spanning the space between said inner ends of said body members, said fixed plate being secured to said body members and carrying one end of a first mounting bushing having its axis parallel to the axes of said alternate pivot bushings, said retaining plate being removably secured to said body members and carrying one end of a second mounting bushing coaxial with said first mounting bushing, the other ends of said first and second mounting bushings being in opposed relation to each other and sized to be fittable within the respective opposite ends of said main pivot bushing.

References Cited by the Examiner UNITED STATES PATENTS REINALDO P. MACHADO, Primary Examiner. 

1. IN A FOLDING TRAMPOLINE HAVING A FRAME INCLUDING LATERALLY SPACED SIDE MEMBERS, SAID SIDE MEMBERS HAVING A PAIR OF MAIN PIVOT MEANS DISPOSED MIDWAY THEREALONG FOR REMOVABLY RECEIVING THE UPPER ENDS OF A PAIR OF ROLLER STANDS OF THE KIND DESCRIBED FOR CARRYING SAID TRAMPOLINE WHEN FOLDED OVER A GYMNASIUM FLOOR, SAID MAIN PIVOT MEANS BEING EFFECTIVE WHEN THE FOLDED TRAMPOLINE IS BEING CARRIED BY SAID ROLLER STANDS TO PERMIT THE FOLDED TRAMPOLINE TO BE ROTATED THEREABOUT ON A FIRST AXIS EXTENDING CENTRALLY AND TRANSVERSELY BETWEEN SAID SIDE MEMBERS TO AN UPRIGHT POSITION WHEREIN THE LOWER END OF THE FOLDED TRAMPOLINE IS SPACED ABOVE THE FLOOR, THE COMBINATION THEREWITH OF A PAIR OF HEIGHT ADAPTERS SECURABLE TO SAID SIDE MEMBERS, SAID ADAPTERS INCLUDING A PAIR OF ALTERNATE PIVOT MEANS CARRIED THEREBY FOR REMOVABLY RECEIVING THE UPPER ENDS OF SAID ROLLER STAND FOR ROTATION OF THE FLODED TRAMPOLINE THEREABOUT ON A SECOND AXIS PARALLEL TO SAID FIRST AXIS, SAID SECOND AXIS BEING LATERALLY DISPOSED TO ONE SIDE OF SAID FIRST AXIS EFFECTIVE TO LOWER THE FOLDED TRAMPOLINE TOWARD THE FLOOR WHEN CARRIED BY SAID ROLLER STANDS AND ALTERNATE PIVOT MEANS AND ROTATED THEREABOUT TO AN UPRIGHT POSITION IN WHICH SAID FIRST AXIS IS DISPOSED BELOW SAID SECOND AXIS. 